Performance + durability of a race part.

Manners + longevity of a stock part.

The best of both worlds.

Over the past 10+ years of building and breaking 4Runners, we have experienced a lot of different rear arm kits. There were lots of options on the market, but there just wasn't anything that checked off all the boxes. So we decided to build our own set of arms, using overkill steel tube, top quality machining, and the industry's gold-standard Johnny Joints®.

Description:

Thick-walled DOM steel:

No more breaking and bending rear arms! 1.625in tube lowers, 1in tube uppers for the best compromise between strength and clearance throughout travel.
Wrench flats for easy adjustment and torquing of the lock nuts.
Powdercoated textured black with etched-in Opt logo.

Adjustable, offset design:

Correct your pinion angle to prevent premature u-joint wear and vibrations (if you have a lift then this applies to you).
Move rear axle position for better tire clearance.
Upper- Double adjustable design, for easy fine tuning after install. No need to uninstall anything to adjust the length. Simply loosen the jam nuts, dial in your lengths, and then tighten the jam nuts back down. Double-adjustable arms also have twice the adjustability length (3in) versus single-adjustable arms.
Lower- Offset joint on one end for better clearance of the oversized joint throughout travel. Lifted trucks tend to have clearance issues at full droop due to the very tight design of the factory axle mounts.

Johnny Joints® throughout: (valued at $66 each, or $528 for a full set!)

Sealed, greasable flex joints with ultra-low maintenance and none of the clanking or squeaking of other flex joints and heims. (our V1 prototypes were used for 5+ years and were never greased or serviced, for testing purposes.) They're serviceable and easily rebuildable, so it's money saved in the long run.
More articulation than stock, polyurethane, heims, and other flex joints. Johnny Joints have an impressive 34-42 degrees of articulation depending on the joint (other brands claim up to 33).
Custom machined for our Toyota trucks (perfect fitment with stock mounts and hardware). To our knowledge, these are the first and only set of rear uppers and lowers that utilize nothing but Johnny Joints! If you aren't familiar with their reputation, click here (short version: they're the best).

Pricing:

Upper Control Arms: $359
Lower Control Arms: $519
Full Kit, Uppers & Lowers: $849 ($29 bundle discount)

Timeline: Lowers in stock ready to ship, uppers backordered until 9/10.

Install Help: Watch Timmy the Toolman’s Install Video HERE (this video was for the 3rd Gen 4Runner kit, but the majority of it all still applies).

FAQs:

Without a poly/rubber bushing at one end, shouldn't I worry about damage to my truck's lower link mounts?

No! We designed the lower arms to include one narrow joint (for articulation) and one wide joint (for cushioning). The 'wide' model JJs have as much built-in cushion as a conventional poly bushing, due to the 2-piece construction of their proprietary urethane bushings. Regardless of your setup, we recommend installing a Lower Link Reinforcement kit on any trail rig, as the potential for mount damage increases the more you upgrade the truck and push the limits.

What should I use to grease the joints?

Any standard Moly Grease will do just fine, but Rock Jock 4x4 has a proprietary Moly Grease that is available in our Rebuild Kit menu.

Is hardware included?

No, we had these Johnny Joints custom built so they are specifically sized for our factory bolts! This helps keep your cost lower and makes installation easier.

Why no adjustable panhard bar?

First and foremost, we recommend a Panhard Correction Kit before upgrading your panhard bar. Adjustable bars are proven to be less effective than a PCK, and more expensive at that. The PCK will solve both the axle recentering issue AND the geometry issue, unlike an adjustable bar by itself. Per eimkeith: "The Panhard Correction Kit returns the panhard bar to horizontal (per original design), eliminates the need for an aftermarket adjustable panhard bar to recenter the axle, and in most cases (up to 4 inches of lift) raises the roll center for improved handling..."

If you are in need of an adjustable panhard bar, check out the Double Adjustable Panhard Bar from KDK Fab.

4th Gen 4Runner Control Arms

Rear Adjustable Control Arms (03-21 4Runner, FJ, GX)